The use of electronic stimulating devices are now well known, and examples of such devices to suppress pain are also now well known (see, for example, in U.S. Pat. Nos. 4,014,347, 4,210,150 and 4,632,117).
It is also well known that such devices have heretofore commonly included fault indicators, such as visual indicators for indicating low battery voltage (see, for example, U.S. Pat. No. 4,632,117).
More recently, it has been found that biphasic pulses can be used to good advantage in connection with electronic stimulating devices, and examples of devices generating biphasic pulses are shown, for example, in U.S. Pat. Nos. 2,375,575 3,946,745, 4,237,899 and 4,256,116.
Still more recently, it has been found that specific groupings of biphasic pulses can be used to increase the activity of selected nerve fibers (see U.S. Pat. No. 4,640,286). It has also been found that specific groupings of biphasic pulses can be used to good advantage with plural equally active electrodes (see U.S. Pat. No. 4,803,988), and, more particularly, with symmetrical biphasic pulses applied through equally active electrodes to one or more channels (see U.S. Pat. No. 4,813,418).
Transcutaneous nerve stimulating devices providing dual channel isolation and including capacitively coupled outputs have also heretofore been suggested for use with monopolar-type stimulation (see, for example, U.S. Pat. No. 4,632,117 wherein a high voltage power supply is connected to the electrodes by transistor switches controlled by control pulses provided thereto by a pulse generator, with the power supply being isolated from the user by a capacitor/diode arrangement so that the device cannot directly deliver any net DC charge to the user, and with a bleeder resistor that discharges the output capacitor during the intervals between the pulses).
Microprocessor controlled transcutaneous nerve stimulating devices have also been heretofore suggested for use with transformer coupled transcutaneous nerve stimulating devices producing a biphasic pulse output (see, for example, U.S. Pat. No. 4,640,286).
Thus, while electronic stimulating devices have been heretofore suggested, and while such devices have heretofore been extensively modified, additional improvements can still be utilized to good advantage.